1) They both talk about how the "mainstream" is out to smear / destroy their "alternative"
2) They both talk about how your mind should not be limited by the "establishment" and they want to show you the way
3) And they've been around for a long time ("in a good sense" is implied)
You can read the rest at
A (MLM) Skeptic: A Common Scam Defense: Similarity Between Homeopathy Advocacy and HYIP promotion